[igt-dev] [PATCH i-g-t 1/3] lib/xe: Add support to reset all GT's

[Kumar, Janga Rahul]

> -----Original Message-----
> From: Brost, Matthew <matthew.brost at intel.com>
> Sent: 11 August 2023 19:32
> To: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Ch, Sai Gowtham <sai.gowtham.ch at intel.com>; Kumar, Janga Rahul
> <janga.rahul.kumar at intel.com>; igt-dev at lists.freedesktop.org; Gandi,
> Ramadevi <ramadevi.gandi at intel.com>; Joshi, Kunal1
> <kunal1.joshi at intel.com>
> Subject: Re: [igt-dev] [PATCH i-g-t 1/3] lib/xe: Add support to reset all GT's
> 
> On Fri, Aug 11, 2023 at 03:52:16PM +0200, Maarten Lankhorst wrote:
> > Hey,
> >
> > Den 2023-08-10 kl. 12:17, skrev Ch, Sai Gowtham:
> > >
> > > -----Original Message-----
> > > From: Kumar, Janga Rahul <janga.rahul.kumar at intel.com>
> > > Sent: Monday, August 7, 2023 9:28 AM
> > > To: igt-dev at lists.freedesktop.org; Gandi, Ramadevi
> > > <ramadevi.gandi at intel.com>; Kumar, Janga Rahul
> > > <janga.rahul.kumar at intel.com>
> > > Cc: Ch, Sai Gowtham <sai.gowtham.ch at intel.com>; Joshi, Kunal1
> > > <kunal1.joshi at intel.com>; kamil.konieczny at linux.intel.com; Karas,
> > > Anna <anna.karas at intel.com>
> > > Subject: [PATCH i-g-t 1/3] lib/xe: Add support to reset all GT's
> > >
> > > From: Janga Rahul Kumar <janga.rahul.kumar at intel.com>
> > >
> > > Introduce xe gt library.
> > >
> > > Add support to check GT reset and force reset all GT's.
> > >
> > > Cc: Sai Gowtham Ch <sai.gowtham.ch at intel.com>
> > > Cc: Kunal Joshi <kunal1.joshi at intel.com>
> > > Cc: Kamil Konieczny <kamil.konieczny at linux.intel.com>
> > > Cc: Anna Karas <anna.karas at intel.com>
> > > Signed-off-by: Janga Rahul Kumar <janga.rahul.kumar at intel.com>
> > > Tested-by: Kunal Joshi <kunal1.joshi at intel.com>
> > > ---
> > >   lib/meson.build |  1 +
> > >   lib/xe/xe_gt.c  | 62
> +++++++++++++++++++++++++++++++++++++++++++++++++
> > >   lib/xe/xe_gt.h  | 27 +++++++++++++++++++++
> > >   3 files changed, 90 insertions(+)
> > >   create mode 100644 lib/xe/xe_gt.c
> > >   create mode 100644 lib/xe/xe_gt.h
> > >
> > > diff --git a/lib/meson.build b/lib/meson.build index
> > > ce11c0715..b7bfcf4f0 100644
> > > --- a/lib/meson.build
> > > +++ b/lib/meson.build
> > > @@ -103,6 +103,7 @@ lib_sources = [
> > >   	'igt_dsc.c',
> > >   	'xe/xe_compute.c',
> > >   	'xe/xe_compute_square_kernels.c',
> > > +	'xe/xe_gt.c',
> > >   	'xe/xe_ioctl.c',
> > >   	'xe/xe_query.c',
> > >   	'xe/xe_spin.c',
> > > diff --git a/lib/xe/xe_gt.c b/lib/xe/xe_gt.c new file mode 100644
> > > index 000000000..9cad739be
> > > --- /dev/null
> > > +++ b/lib/xe/xe_gt.c
> > > @@ -0,0 +1,62 @@
> > > +/* SPDX-License-Identifier: MIT */
> > > +/*
> > > + * Copyright © 2023 Intel Corporation
> > > + *
> > > + * Authors:
> > > + *    Janga Rahul Kumar <janga.rahul.kumar at intel.com>
> > > + */
> > > +
> > > +#include <fcntl.h>
> > > +
> > > I don’t think new line is needed here.
> > > +#include "xe_gt.h"
> > > +
> > > +/**
> > > + * has_xe_gt_reset:
> > > + * @fd: open xe drm file descriptor
> > > + *
> > > + * Check gt force reset sysfs entry is available or not
> > > + *
> > > + * Returns: reset sysfs entry available  */ bool
> > > +has_xe_gt_reset(int
> > > +fd) {
> > > +	char reset_sysfs_path[100];
> > > +	struct stat st;
> > > +	int gt;
> > > +	int reset_sysfs_fd = -1;
> > > +	int sysfs_fd = -1;
> > > +
> > > +	igt_assert_eq(fstat(fd, &st), 0);
> > > +	sysfs_fd = igt_sysfs_open(fd);
> > > +
> > > +	igt_assert(sysfs_fd != -1);
> > > +	xe_for_each_gt(fd, gt) {
> > > +		sprintf(reset_sysfs_path,
> "/sys/kernel/debug/dri/%d/gt%d/force_reset",
> > > +				minor(st.st_rdev), gt);
> > > +		reset_sysfs_fd = openat(sysfs_fd, reset_sysfs_path,
> O_RDONLY);
> > > +
> > > +		if (reset_sysfs_fd == -1) {
> > > +			close(sysfs_fd);
> > > +			return 0;
> > > +		}
> > > +
> > > +		close(reset_sysfs_fd);
> > > +	}
> > > +
> > > +	close(sysfs_fd);
> > > +	return 1;
> > > +}
> >
> > We can reset a gt by only opening a file in debugfs? That seems like a
> > terrible api, we should probably force it to only reset by writing 1
> > or something instead..
> >
> 
> Yea this was my lazyness when adding, agree we should fix this in the KMD.
Pls update the igt lib as well along with KMD fix.

Thanks,
Rahul
> 
> Matt
> 
> > Cheers,
> >
> > ~Maarten
> >